REVIEW

BOTTOM LINE: A likable send-up of the teen genre, with Hill and Tatum making an effective and even endearing comic team.

CAST: Jonah Hill, Channing Tatum, Brie Larson, Ice Cube

LENGTH: 1:43

Jonah Hill is entering dangerous waters with "21 Jump Street," an intentionally comedic spin on the straight-faced, late-1980s Fox television series. Starring a 20ish Johnny Depp as an undercover cop improbably blending in with high-schoolers, the show was a good example of the hilarity that ensues when show biz oldsters try to speak "teen." Hill, though a youthful 28, is not only mocking a mockery, he's also facing some of the same hokey old traps.

But the saving grace of "21 Jump Street," co-written and produced by Hill, is its obvious affection for teen genres, and for teenagers. Though ostensibly an action-comedy with car chases and gunfights, the movie works best as a commentary on the ever-changing and always baffling rules of youth culture, with Hill and Channing Tatum as the bumbling cops Schmidt and Jenko, who are sent back to school to mix, mingle and stop crime.

The best jokes are in the setup: Schmidt, a former outcast, is delighted to find that today's popular kids are sensitive, gay-tolerant types, while Jenko, once a bullying jock, is horrified. (He blames "Glee.") Chubby Schmidt falls in with school-ruler Eric (Dave Franco, younger brother of James) and pretty Molly (an appealing Brie Larson) while the strapping Jenko is thrown in with the science geeks -- a subset that apparently never goes away.

The movie mocks many a teenage trope, such as a new drug with an unprintable acronym and a clear nod to the "U4EA" that Jason Priestly ingested in "90210" -- but it works better when it takes Schmidt and Jenko at least somewhat seriously. They make an endearingly likable pair, and Tatum is quite sweet and funny in a role that finally focuses on more than his pecs. Even in a teen-movie spoof, there's always room for sincerity.

PLOT Two bumbling cops go back to high school disguised as students. RATING R (language, crude humor, drug use)

BOTTOM LINE A likable send-up of the teen genre, with Hill and Tatum making an effective and even endearing comic team.

Back story: How stars jumped into 'Street'

The idea of remaking "21 Jump Street" was pitched to Jonah Hill around the time of his success in "Superbad." While he was "not a massive fan of the show," his interest sparked when he saw it as a story of adults reverting to the immature behaviors and insecurities they thought they'd outgrown.

"The movie I was interested in creating was like 'Bad Boys' meets a John Hughes movie," said Hill, who co-wrote the screenplay.

Co-star Channing Tatum, who had never before attempted comedy, figured he wouldn't get a better apprenticeship than working alongside Hill.

"He promised me he'd take care of me and that was really the whole reason of me jumping on to this thing. It took some assuring.I was open to challenging myself like this and then he had to hold my hand and stroke my head and tell me that everything was going to be OK. I told him I'd blame it on him if I wasn't funny," and that was my out,Tatum said.

"I was a fear-driven beast the whole time, to not let Channing down," said Hill. As an actor and a producer,"I've been on both sides of being convinced to be in a movie and having to convince other people to be in a movie.The best thing ever is when you meet someone you like and respect and they're just cool about diving into something different."